Impact of tumour characteristic and treatment modality on the local recurrence and the survival in patients with oral squamous cell carcinoma.

Summary Purpose of the study To evaluate the impact of tumour location, local and regional advancement, histological differentiation, status of the surgical margins and radiotherapy on the disease-free time and overall survival rates in patients with oral squamous cell carcinoma. Material and methods A retrospective analysis of 67 patients treated with surgery (61 pts.), radiotherapy (6 pts.) and their combination (28 pts.). Follow time on average 40 months. The probabilities of survival were assessed using the Kaplan-Meier estimates, the differences were calculated with the log-rank test. An analysis of the influence of the neck recurrences on the prognosis was additionally performed. Relationship between independent categorical variables as: primary local advancement, location of the tumour, histological grading and lymph node metastases was evaluated with Fisheŕs Exact Test. Results Disease-free time rate amounted to 40,1%. There was no independent prognostic importance of primary location, T-staging and N-staging, histological grading of the tumour or radiation on disease-free time, just opposite to the status of the resection margins. However, the number of neck metastases was directly proportional to the tumour dimension and poor histological differentiation. Overall survival rate amounted to 87,5%. Posterior location in the oral cavity, involvement of cervical lymph nodes, surgical margins with the presence of tumour cells, poor histological differentiation and necessity of irradiation negatively correlated with the survival. Conclusions A complete resection of the tumour was the most important independent prognostic parameter for the disease-free and overall survivals in oral squamous cell carcinomas in this study. An adjuvant radiation therapy could improve the results of treatment of oral squamous cell carcinoma also in cases were so far considered only for surgical management.